Rheostat



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Oct. 28 1924.

Oct. 28 1924.

F. F. HlL.l lX

RHEOS TAT Filed March lO, 192?. 2 Sheets-Sheet 2 Mfg/L Patented ct. 2`8, 19?..4.v

.UNITEOSTATES PATENT OFFICE.

FOSTER F. IIILLIX, OE CLEVELAND, OHIO, AsnsIcNoR To WHITE SEWING MACHINE COMPANY, OF CLEVELAND,l OHIO, A CORPORATION OF O-H.Io.

RHEOSTAT.

Application led March 10, 1922. Serial No. 542,687.

To all 'whom t may concern.:

Be it known that I, FOSTER F. I-IILLIX,

citizen of the United States, residing at Cleveland, in the countyof Cuyahoga and\ has special reference to rheostats adapted to l be employed in connection with small motors Asuch as motors for operating sewing machines and the like.

The principal object of the present invention is to provide a rheostat which is etlicient, and very substantially constructed, and which can be inexpensively produced in quantities.

^ Still further the aim of the invention is to so construct the rheostat that the use of screws or equivalent fastening means for assembling or fastening the parts in assembled relationship is entirely avoided.

The invention may be briefly summarized as consisting in certain novel/details of Construction, and combinations and arrangements of parts which will be described in the speclication'and pointed out in the appended claims. p

In the accompanying sheets of drawings, Fig. 1 is a perspective view of a rheostat constructed in accordance with my invention; Fig. 2 is a view of the rear side of the same; Fig. 3 is a bottom view of the same; Fig. 4 is a vertical sectional view substantially along the line 4-4 of Fig. 7; Fig. 5 is a top plan view; Fig. 6 is a detail of a part of thecover member in the process of its manufacture, showing particularlythe manner in which the insulating blocks supporting the'terminals are attached to the cover; Fig. 7 is a view with the cover member in section and with the front half or part of the casing removed; Fig. 8 is an inside view of the front half of the casing omitted from Fig. 7 Fig. 9 is a detached `view of the rheostat unit which is enclosed dat rectangular form, and composed of a a main body member 10, la front body member 11, and a flanged cover member 12 which projects beyond the margin of the body of the casing and is provided with openings 12a by which the rheostat may be fastened to a' suitable support. The cover member carries two pairs of terminals 13 and 14 by which the rheostat may be connected to line conductors, and to the motor, these terminals being supported in a manner to be explained subsequently.

The casing members 10, 11 and 12 are stamped from comparatively thin sheet metal, and the flat oppositel sides of the members 10 and 11 are preferably provided with Ventilating openings or slots 15. On three sides the members 10 andv 11 have marginal portions 10a and 11a which are struck up, and the struck up portions are held together by integral tongues 10b and l1b at the corners, forming box-like structures. At the top next to the cover member 12 the ends of both members are open, i. e. do not have the struck up portions 10' and 11a. Also it will be observed that the portions 10H and 11a are adapted to abut when the two parts are closed one on the other to form the closed casing, and it will be noted also that these parts are held together byV ears 10o, struck up from the part 10, and by tongues 11c on the part 11 and received in the ears. After the tongues are extended through the ears, the ends of the tongues are bent or deflected by a suitable tool to hold the casing parts 10 and 11 together in the manner shown in Fig. 1. y

The cover 12 is fastened to the member 10 of the casing by means of tongues 10d (see Figs. 1, 5, and 10), projecting up from the top of the member 10 of the casing through slots 12a of the cover member 12, the portions of the tongues extending through the cover memben 12 being bent laterally by a suitable tool to securely fasten the cover member to the body member 10.

Inside the casing is what may be termed the switch or resistor unit, which comprises a substantially rectangular body 16, generally formed of porcelain, and having its front, back and ed e faces grooved to receive a resistance wire 17, (see particularly Fig. 9). This resistor element or unit Carto the resistance wire, these buttons being arranged in arcuate forms. Additlonally the resistor unit carries a sw1tc h arm 19 pivotally connected to the porcelain body by a rivet or equivalent means so that its free end may sweep over the contact buttons, the last/f of which is preferably disconnected from' the resistance wire so as to enable the motor circuit to be broken at this point, this being the off position ofthe switch 19. Y

Additionally the resistor unit carries two connectors 21 and 22, the former beine` electrically connected tothe switch arm and the latter to the contact button 18 connected to one end of the resistance wire 17 Both these connectors 21 and 22 a're formed from stampings,

'body clearly shown inF ig. 7, andat their upper ends are bent laterally so that they may be connected to two of the-terminals` 13 and 14 when the cover member 12 carrying these terminals is fitted to the body member 10 as will bcexplained.

This resistor unit ceived vinto the body member 10 of the casing and is held iirmly therein by one o-r more tongues 10 onthelower part of the member 10, and by a tongue or clip 10f which is at the top ot' the body member 10 and projects across beneath the cover member 12 and across the top of the porcelain 16.

In assembling, the resistor unit is slippedl into the case with its top under the free edge otl the clip 10f which can be sprung -back slightly it necessary, and then the lower tongues 1()e are driven in by a tool to hold the resistor unit in place, the porcelain being notched out it necessary, to receive the lower tongues 10e. f It is to be noted in passing, that the switch arm 1S) is provided with a laterally projecting operating pin 19a.

The front member 1l of the casing carries a rheostat operating member, in this instance in the form of a slide 23, this slide projecting from the bottom of the casing, where it is provided with a laterally projecting extension 23a adapted to be engaged by any suitable opera-ting part to operate the rheostat. Usually the slide 23 is shifted by a part controlled by the foot or hand, depending upon 4the particular machine or apparatus with which the rheo-stat and motor are used. My invention has especial utility in the. control of sewing machine motors, in which event the rheo-stat may be shifted either by a manual or toot controlled part.

F This slide is held to the inner face of the front member 11, partly by the bottom portion of the member 11, at the point' Where it is slotted to permit the slide to extend therethrough, and partly by a pair and they project upwardlyl is adapted to be re-v of inwardly bent ears 11d' stamped from the face of the fronti member 11.

In order that the slide 23l mayf operate is made of wear resisting insulating material is preferably held to the slide by ears 23 struck on the slide and bent around the endsl of the block into the grooves 24B. Additionally the front member 11 carries a Spring 25, of any suitable type for 4holding the slide and switch arm in off position.

The slide has a limited vertical movement in the lfront member 11 of the easing, its up and down movement being limited `by definite stops. In this instance the upward movement. isA limited by engagement of the block 24 with the ears 11d, and its downward, movement is limited 'by a tongue 23 struck up from theslide and adapted to engage the lower wall of the front member 11 of the casing as is apparent from Fig. 8. As before stated, the cover member 12 carries two sets of terminals 13 and 14. The terminals of each p air are adjacent each other, and they extend down through a pair of insulating blocks or plates 26, these being ot rectangular shape. The terminals and the insulating blocks 26 are held in the cover in a very effective manner, as will bel observed by reference particularly torFigs. 1, 6 and 7. In blanking out the cover, rectangular openings 12b are cut in the cover where the terminals are to be leaving protruding corner portions 12d i which are indicated in Fig. 6. When the lips or flanges are struck up in the manner illustrated in Figs. 1, 5 and 7, they form a` space of suiiicient size to receive the upper insulating block 26 through which the'termin-als pass, and the block is thus supported on the corner projections 12d. In fact, the pair 'of blocks .are clamped one onto the top of the cover member and the other on the bottom or inner side thereof on opposite sides of these corner pieces, and they are llield in this position by the terminals 13 and One terminal 13 and one terminal 14 are connected together by a connector 27, this connector being preferably secured to the ends of the terminals by expanding themx to be electrically connectedto the upper ends of the connectors 21 and 22 previously referred to, and described as being carried by the resistor unit. That is to say, in attaching the cover member 12 to the top of the body member 10 of the casing with the resistor unit in the latter, the lower ends of the two terminals 13 and 14 will, in the assembling be extended through openings 1n the upper laterally projecting ends of the conductors 21 and 22, and after they are thus assembled the lower ends of these terminals can be expanded to firmly secure these connectors to them in the same way that the other pair of terminals 13 and 14 were described as being fastened to the top cross connector 27.

It will be seen from the above construction, that the rheostat, is composed chiefly of four units, which are as follows: the body member 10 of the casing, the front member 11 of the casing with its slide, the cover member 12 of the casing with its two pairs of terminals, and with lthe connector connecting one terminal of one pair to one terminal of the other pair, and the resistor unit with its resistance wire, contact buttons, switch arm and connectors 21 and 22.

Assuming that these units are formed and the parts assembled thereon as already described, in completing theassembly of the rheostat the resistor unit is slipped into the body part 10 of the casing and held therein by the tongues 10e and 10f. Next the cover member 12 is fitted onto the top of the body member 10 of the casing, and in so doing,

ltwo of the terminals 13 and 14 are electri -the cover member, and then the lower ends of the terminals connected to the upper ends of the connectors 21 and 22 are expanded to securely fasten these. terminals to the connectors. Then the front member 11 is fitted .onto the body member 10 with the cross slot in the block 24 of the slide receiving the laterally projecting pin of the switch arm 19, and when this is done, it is only necessary to bend laterally the tongues .11c which in the assembling are extended'through the ears 10c of the body part of the casing. Y This completes the assembling of the several units of the rheostat which is now ready for use.

Thus it will be seen that the parts are very largely formed by press work, i. e. from sheet metal stampings which can be blanked out with rapidity and lin large quantities, and that the parts are fastened together without the necessity of attaching screws or equivalent means, the operations necessary to attaching the parts consisting almost altogether of upsetting by expanding tools the Having 4described my invention, I claim:

1. In combination in a rheostat, a casing comprising a body member and a cover member, a switch unit received in the body member and comprisingan insulating block bearing resistance material, said cover member adapted to be fitted onto the body member and provided with a terminal, and means through which said terminal is electrically connected to said switch unit when the cover member is fitted into place.

2. In combination in a rheostat, a casing, a resistor unit enclosed thereby and including an insulating body and resistance material supported by it, the casing including a body portion having front and back members, one enclosing the resistor unit and the other supporting on the interior thereof adjacent the face of the resistor unit a rheostat operating member.

3. In combination in a rheostat, a casing, a resistor unit enclosed therein and composed of an insulating body supporting resistance material, contacts, and a switch arm, said casing composed of a pair of complementary members fastened together, one receiving the resistor unit and the other carrying a rheostat operating member, said member being operatively connected to the switch arm when the two parts of the casing are fitted together.

4. In .combination in a rheostat, a sheet metal easing composed of complementary front and back members, and a resistor unit received in one of said casing members, the latter having integral tongues for engaging and holding the resistor unit. l

5. In combination in a rheostat, a sheet metal casing composed of complementary front and back members, and a resistor unit received in one of said casing members, the latter having integral tongues for engaging and holding the resistor unit, and said two parts of the casing being provided respectively with locking tongues and tongue receiving openings by which said parts are fastened together.

6. In combination in a rehostat, a casing comprising a body member and a cover member, a resistor or switch unit received in the body member and comprising an insulating block bearing resistance material and also a connector attached to a suitable part of the switch unit, and Said cover member adapted 7. In combination in a rheostat, a casing` comprising a lbody* member and a cover member, a switch unit in the body member and provided with an insulating block carrying resistance Wire and a pair of connectors connected to suitable parts of the switch unit, said cover member adapted to be fitted to and secured to the body member and provided with a pair of terminals which are of terminals, and means whereby two ofsaid terminals are connected to two switch -or resistor unit whent e cover is fitted into place.

a switchl or resistor unit therein and com-f' Aprising an insulating block bearing resistance wire, a switch arm, acover member having a plurality of terminals secured thereto and adapted to be electricallyV connected to suitable points of the switch unit,

the cover member having openings formed vtherein through which the terminals extend,

electrically connected to said connectors\and having insulating members located at when the cover member is fitted into place.

8. In combination in a rheostat, a casing having a body member anda cover member,

a switch or rheostat unit inthe body member provided with an insulated-block car-v rying resistance wire, and a pair of connectors connected to suitable parts of the switch unit, the cover member adapted to be fitted to and secured to the body member by tongues on one part and openings in the other adapted to receive the tongues, and the cover member having a pair of terminals adapted to be electrically connected to said connectors.

9. In combination ina rheostat, a sheet metal casing composed of several parts including a body member and a cover member, a switch or resistor unit in the body member and comprising an insulated block carrying resistance material, the top ofthe body member having a plurality of upstanding tongues and the covermember having a plurality of openings adapted to receive the tongues, and provided also with a plurality of terminals.

v10. In combinationin a rheostat, a sheet metal casing -composed of several parts including a body member and a cover member, a switch or resistor unit in the body member and comprising'an'insulated block carrying resistance material, thel top of the body member having a plurality of upstanding tongues and4 the cover member having a. plurality of openings adapted to receive the tongues, and provided also with a plurality said openings and clamped on opposite sides of the cover adjacent said openings, said terminals being electrically connected to suitable points of the switch unit. y

12. In combination in a rheostat, a casing comprising a'body member and a cover member, a switch unit in the body member, the

cover member having'rectangular openings 70 formed therein, and lips bent laterally of the cover member and bounding said openings With integral corner projections at the openings, a pair of insulating blocks at said openings, and clamped on opposite sides of the corner projections, with certain of the blocks received in said lips, and terminal .members extending through said blocks.

13. In a rheostat, a sheet metal casing comprisin back mem ers,`one having tongues and the other openings receiving said tongues Whereby vthe parts are fastened together, a cover l -member fitted onto one of the body members, and one of the same having openings and the other tongues received in said openings, whereby said body member and cover are securedtogether, a switch or resistor unit within the body, and terminals carried by the cover member and electrically connected to suitable parts of the switch or resistor unit.

In testimony whereof, I hereunto aliix my signature.

FOSTER r. HILLIX.-

arts of the 50 11. In combination in a rheostat, a casing,./

a body composed of front and 80 

